For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningInstallation Procedure
Cut the roof front header panel in corresponding locations to fit the
remaining original panel. The sectioning joint should be trimmed
to allow a gap of one-and-one-half-times the metal thickness at the
sectioning joint.
Create a 50 mm (2 in) backing plate from the unused portion of ...
Jump Starting
If the battery has run down, try to use another vehicle and some jumper cables to start your vehicle.
Be sure to use the following steps to do it safely.
WARNING
Batteries can hurt you. They can be dangerous because:
• They contain acid that can burn you.
• They contain gas ...
Rear Compartment Lid Emblem/Nameplate Replacement (VCDi AT)
Rear Compartment Lid Emblem Assembly
Caution: Refer to Exterior Trim Emblem Removal Caution in the
Preface section.
Procedure
The part and surface should be 21°C (70°F) prior to installation. The
vehicle should remain 21°C (70°F) for
one hour after assembly to allow adhesive to deve ...